Publication/Presentation Date

11-1-1993

Abstract

BACKGROUND AND PURPOSE: Current noninvasive testing allows accurate assessment of cerebrovascular hemodynamics. The cardiovascular influence on the noninvasive assessment of cerebrovascular studies has not been defined. This study was designed to determine the effect of cardiac index (CI) on cerebral blood flow velocities, ocular pulse amplitude, ophthalmic systolic pressure, and ocular blood flow (OBF) as currently estimated by noninvasive laboratories.

RESULTS: The relation between OBF and CI is expressed by the equation CI = 2.36 + 0.61 x OBF (r = .47, P = .0010). The middle cerebral artery peak systolic velocities and CI had a correlation of .36 (P = .0181). The equation, derived from the linear relation between OBF and CI, was then validated on a sample of 15 patients. With the apparent linear relation between OBF and CI, we used the derived equation to predict CI from OBF. The OBF determination predicted CI within 30% in all patients and within 20% in 53.3% of the patients.

CONCLUSIONS: We demonstrated that OBF and middle cerebral artery systolic velocity decrease with diminishing CI. Our findings suggest that CI may be potentially estimated in selected patients by noninvasive assessment of OBF using ocular pneumoplethysmography.